Flexible Pouch With Tear Line

ABSTRACT

A flexible pouch, particularly for foodstuffs of the moist type, having a line of preferential tearing in which two side walls are rendered integral by at least a sealing line and the line of preferential tearing provided in one of the two side walls. The line of preferential tearing extends along the sealing line, the distance (a) between the line of preferential tearing and the sealing line being less than or equal to 10 mm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase filing of PCT/EP2004/006642 filedJun. 18, 2004 claiming priority to FR 0307489 filed Jun. 20, 2003.

TECHNICAL FIELD

The present invention relates to a flexible pouch especially forpackaging foodstuffs and having at least one line of preferentialtearing.

BACKGROUND OF THE INVENTION

It is known to use flexible pouches for packaging moist foodstuffs,especially for animals.

In particular, WO 98/29312 discloses such pouches. The pouches have tworectangular side walls secured by sealing along their edges. The pouchesare sealed closed after filling. These side walls are made from filmshaving a particular structure because of the treatments of sterilizationby heating in a moist atmosphere and under pressure to which the pouchesare subjected. Typically, such a film comprises a polyethyleneterephthalate (PET) layer defining the outer layer of the pouch and apolypropylene (PP) layer defining the inner layer of the pouch and analuminium layer sandwiched between the two previous layers.

This type of pouch is difficult for the user to open without resortingto scissors or a knife, because of the mechanical strength of the filmsforming it.

In order to make them easier to open, this document proposes producingone or two parallel lines of preferential tearing in each side wall ofthe pouch in the upper part of the pouch, the line(s) of preferentialtearing of the first side wall being substantially superimposed withthat (those) of the second side wall. The line(s) of preferentialtearing of each side wall extend over virtually the entire width of thepouch.

Because the side walls are preweakened along the lines of preferentialtearing, the user may open the pouch with only his hands by tearing thepouch in the region of the lines of preferential tearing. The userinitiates the tear from a side edge of the pouch, then continues tearingtowards the other side edge. The tear propagates along the line ofpreferential tearing in each side wall when there is only one of themper side wall or along one of the two or between the two when there aretwo of them per side wall. Thus the lines of preferential tearing guidethe tear up to the other side edge of the pouch.

Where each side wall of the pouch has two parallel lines of preferentialtearing, a notch is made in at least one side edge at a level betweenthe two lines for the purpose of making it easier to initiate the tearthrough the lateral seal.

In practice, the height of the upper seal on such a pouch is limited tosave on a material. Further, the line(s) of preferential tearing areplaced in an upper region of the pouch to allow the pouch to be openedfrom the top while avoiding accidentally spilling its contents while thepouch is being opened. However, the line(s) of preferential tearingis/are arranged at a certain distance from the top seal of the pouch toenable the user to grasp that part of the pouch extending above thelines of preferential tearing with his fingers when opening the pouch,this part then being detached from the pouch.

Nevertheless, it sometimes happens that during the opening operation,the tear leaves the line of preferential tearing when there is only oneper side wall or the zone defined by the two parallel lines ofpreferential tearing when there are two of them per side wall. The tearmay then propagate towards the bottom of the pouch and there is a riskthat the foodstuffs may be accidentally spilled during opening.

Furthermore, before opening the pouch, the user is recommended to shakethe pouch by holding it at the top so as to make any foodstuffs that maybe present in the top of the pouch in the zone of the lines ofpreferential tearing go down. Alternatively or additionally, the usermay also smooth the upper zone of the pouch between his fingers from thetop downwards for the same purpose. Thus, the foodstuffs are found belowthe level of the lines of preferential tearing. Without carrying outthis prior operation, it is not very probable that the tear for openingthe pouch will propagate effectively along the lines of preferentialtearing, due to the presence of foodstuff at the line of preferentialtearing. Additionally, there is a danger of the user being spattered bythe food content present at the lines of preferential tearing, even whenopening is done correctly. These problems are particularly significantwhen the pouch contains moist foodstuffs—or other solid moistproducts—as they have a tendency to stay at the top of the pouch even ifit is held vertically, unlike dry foodstuff or liquid. Nevertheless,this operation prior to opening the pouch may be felt to be tedious bythe user. Moreover, it has been found that the user often forgets tocarry out this prior operation before tearing the pouch for opening.

EP-A-0,473,517 and EP-A-0,596,747 each disclose a pouch with lines ofpreferential tearing arranged similarly to those in the document aboveand having the same disadvantages.

The aim of the invention is to at least partially reduce one and/or theother of these drawbacks.

The invention particularly aims to provide improved guiding of the tearwhen the pouch is opened by the user.

BRIEF SUMMARY OF THE INVENTION

For this purpose, the present invention provides a flexible pouchcomprising:

two side walls rendered integral by at least a sealing line; and

a line of preferential tearing provided in one of the two side walls,

in which the line of preferential tearing extends along the sealingline, the distance between the line of preferential tearing and thesealing line being less than or equal to 10 mm.

In preferred embodiments, the pouch can comprise one or more of thefollowing features:

the distance between the line of preferential tearing and the sealingline is less than or equal to 8 mm, preferably to 6 mm, moreadvantageously to 4 mm, even more advantageously to 2 mm, even to 1 mm.

the line of preferential tearing extends facing at least one edge of thepouch.

the distance between the line of preferential tearing and a pouch edgenearest the line of preferential tearing is greater than 9 mm.

the pouch edge facing the line of preferential tearing and which is theclosest to the line of preferential tearing is the upper edge of thepouch.

the sealing line is provided along the upper edges of the side walls.

the line of preferential tearing extends from an edge of the pouch.

the edges of the walls corresponding to the said edge of the pouch fromwhich the lines of preferential tearing extend are sealed together and anotch is made in the sealing zone of the said edges of the walls at theline of preferential tearing.

the side edges of the walls corresponding to the said edge of the pouchfrom which the line of preferential tearing extends are sealed togetherand a notch is made in the sealing zone of the said edges of the wallsat a level intermediate between the line of preferential tearing and thesealing line, preferably half way between the line of preferentialtearing and the sealing line.

the distance between the edge of the sealing line towards the line ofpreferential tearing and the edge of the pouch facing which the line ofpreferential tearing extends and which is the closest to the line ofpreferential tearing, is greater than 9 mm.

the pouch edge from which the line of preferential tearing extends is aside edge of the pouch.

the line of preferential tearing extends to a second edge of the pouch.

the edges of the walls corresponding to the second edge of the pouch aresealed together.

the second edge of the pouch to which the line of preferential tearingextends is a second side edge of the pouch.

the pouch comprises another line of preferential tearing provided in theother of the two side walls, this other line of preferential tearinglying opposite the line of preferential tearing provided in the first ofthe two side walls.

the pouch comprises a second line of preferential tearing provided inthe side wall in which the first line of preferential tearing isprovided, the second line of preferential tearing extending parallel tothe first line of preferential tearing, the distance between the twolines of preferential tearing being less than or equal to 8 mm.

two other parallel lines of preferential tearing are provided in theother of the two side walls, the two other lines of preferential tearingextending opposite the two lines of preferential tearing provided in thefirst of the two side walls.

each side wall is made from a film comprising a light-metal layer heldbetween two plastic layers.

the width of the sealing line is greater than 9 mm.

the pouch comprises several sealing lines forming a multi-line sealingstrip, the width of this strip being greater than 9 mm.

the or each sealing line is either heat welded, or produced byultrasound welding.

the pouch is sealed against gas.

each side wall in which is provided a line of preferential tearing ismade from a film comprising at least one plastic layer.

the pouch is of the type intended to undergo heat treatment forpreservation treatment.

the line of preferential tearing(s) is/are arranged for providing accessto a content packaged in the pouch upon tearing the pouch along theline(s) of preferential tearing.

The invention also relates to the use of the pouch for packagingfoodstuffs, particularly of the moist type and/or of the loose-producttype.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will become apparent onreading the following description of a preferred embodiment of theinvention, given by way of example and with reference to the appendeddrawings.

FIGS. 1 a, 1 b and 1 c show a package of the pouch type seen from thefront, in cross section and in three-quarter perspective, respectively.

FIG. 2 shows a side wall of the pouch of FIG. 1 with the sealing zones,the side wall having a single line of preferential tearing according tothe invention.

FIG. 3 is a partial view of the side wall of the pouch showing how tomeasure the distance between a line of preferential tearing and asealing line when the line of preferential tearing consists of oblongholes.

FIG. 4 is a view of a side wall of the pouch with its upper part removedby tearing along the line of preferential tearing so as to illustrateanother way to measure the distance between a line of preferentialtearing and a sealing line.

FIG. 5 shows a side wall of the pouch of FIG. 1 with the sealing zones,the side wall having two lines of preferential tearing according to theinvention.

FIG. 6 shows the partial opening of a pouch corresponding to FIG. 5.

FIG. 7 is a partial view of the pouch corresponding to FIG. 5 with theupper edge not sealed.

FIG. 8 is a partial view of the side wall of the pouch showing how tomeasure the distance between two lines of preferential tearing when theyconsist of oblong holes.

FIG. 9 is a partial view of a side wall of the pouch with its upper partremoved by tearing along the two lines of preferential tearing so as toillustrate another way of measuring the distance between two lines ofpreferential tearing.

FIG. 10 shows a side wall of a pouch according to an alternativeembodiment.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a flexible pouch having two side walls sealedtogether along at least one line. The pouch comprises at least one lineof preferential tearing in at least one of the side walls. According tothe invention, the line of preferential tearing extends close to thesealing line along the latter, preferably parallel thereto. Moreparticularly, the line of preferential tearing is advantageously placedat a distance less than or equal to 10 mm from the sealing line.

The closeness of the line of preferential tearing to the sealing linesubstantially improves the guiding of the tear along the line(s) ofpreferential tearing or between them when the pouch is opened by a user.This improvement results from the fact that the sealing line joining thetwo side walls of the pouch together gives increased stiffness to theneighbouring zone of the pouch in comparison with the zones of the pouchfurther away from the sealing zone.

Furthermore, where the two side walls each have at least one line ofpreferential tearing which substantially correspond to each other, thetwo side walls in the zone of the lines of preferential tearing remainclose to each other. Consequently, the corresponding lines ofpreferential tearing of the two side walls are also close, which has theeffect of promoting the guiding of the tear along the lines ofpreferential tearing.

Moreover, when the line(s) of preferential tearing extend(s) from oneside edge of the pouch towards the other, in particular along a sealingline made along the upper edge of the pouch and when it contains looseproducts, in particular moist foodstuffs, merely taking the pouchvertically has the consequence of releasing the products contained closeto the sealing zone downwards. Specifically, the product contents slidein the direction of the bottom of the pouch under the effect of theirown weight and consequently the zone of the line(s) of preferentialtearing is freed without any other user intervention. In particular, theuser does not need to shake and/or to smooth the top of the pouchdownwards before opening in order to release the product contentspresent in the zone of the line(s) of preferential tearing.

A preferred embodiment is now described in relation to FIGS. 1 and 2.

The pouch taken as an example is of the type known per se as “Doypack®”,that is to say a wedge-shaped pouch with a surface forming a baseallowing the pouch to stand upright.

It has two side walls 100, 101 facing each other and secured togetheralong their side edges 2, 3 by sealing. The lower edges 4 of the sidewalls 100, 101 are connected together by a base 102 attached to thelower edges of the side walls by sealing. The base 102 allows the pouchto stand upright.

After filling, the pouch is closed by a seal 9 hermetically joining thetwo side walls 100, 101 along the upper edge 1 of the pouch.

As illustrated in FIG. 2, one of the side walls has a line ofpreferential tearing 5 extending close to the sealing line 9 providedalong the upper edge 1 of the pouch.

When the package is designed to contain foodstuffs, especially moistfoodstuffs, the side walls of the pouch are preferably made from a filmallowing the pouch to be subjected, after filling and sealing, to apreservation treatment, in particular heat treatments such asconventional sterilization, flash sterilization and pasteurization.

To this end, the side walls may be made from a multilayer film having alayer made from a light metal, preferably aluminium, sandwiched betweentwo plastic layers.

The plastic layer defining the outer face of the pouch is preferablymade of polyethylene terephthalate. It contributes to protecting thelight-metal layer against mechanical stresses and also allows printing.

The light-metal layer forms a barrier to external gas, especially tooxygen and steam, in order to isolate the foodstuffs contained in thepouch.

The plastic layer defining an inner face of the pouch is preferably madeof polypropylene (PP). It serves as a welding agent to allow the edgesof the pouch to be sealed by welding. Furthermore, polypropylene givesmechanical strength to the pouch and also contributes to protecting thelight-metal layer.

Optionally, the outer plastic layer comprises a polyamide (PA) layerlocated between the polyethylene terephthalate (PET) layer and thelight-metal layer. Alternatively, it is the inner plastic layer whichcomprises a polyamide (PA) layer located between the polypropylene (PP)layer and the light-metal layer. Such a polyamide layer contributes tomechanically strengthening the pouch.

The various layers of the film are secured to each other using anadhesive coating between the various layers comprising the film.

The polyethylene terephthalate layer preferably has a thickness ofbetween 10 and 20 μm.

The central aluminium layer preferably has a thickness between 7 and 12μm.

The polypropylene layer preferably has a thickness between 30 and 100μm, more preferably between 30 and 60 μm.

When it exists, the polyamide layer preferably has a thickness between10 and 20 μm.

The sealing line 9 may be produced by any suitable technique.

In particular, it may involve heat sealing. In this case, it isadvantageous to produce the sealing line 9 in the form of a heat-sealedstrip having a relatively large width “b”. This is because the sealingline 9 gives stiffness to the pouch in the neighbouring zone whichstiffness is all the greater the wider the zone. Consequently, theguiding of the tear along the line of preferential tearing 5 is therebyimproved. Moreover, in view of the closeness of the line(s) ofpreferential tearing to the sealing line 9 (as will be seen below), agreater width at this point enables the user to get a better grasp onthe pouch at the seal, when opening the pouch. It is consequentlyadvantageous for the sealing width “b” to be greater than or equal to 9mm, preferably to 11 mm, more advantageously to 13 mm, or even 15 mm. Asagainst this, it is preferable for the width “b” to be less than orequal to 30 mm, or even 25 mm, to limit the amount of film required toproduce the pouch.

Regardless of the shape of the pouch and the arrangement adopted for theline of preferential tearing, it is to be understood that the width “b”satisfies, for each point or at least on average, any one of thesepreferred minimum limits over the whole length of the seal line facingthe line of preferential tearing 5. It is even more advantageous for thewidth “b” to satisfy—for each point or at least on average—any one ofthese preferred minimum limits throughout the length of the seal line,i.e. from side edge 2 right up to side edge 3 in our example.

The sealing line 9 may also be made by ultrasound sealing as described,for example, in WO 00/20191. When the sealing line made by ultrasound orotherwise is of small width, for example about 1 mm, it is advantageousto make two or three—or even more—parallel sealing lines between thosewhich define a multiline sealing strip of width “b” of minimal value asdefined above in the case of heat sealing in the form of a single wideline. This plurality of lines has the effect of even further stiffeningthe pouch near these lines in a manner similar to the aforementionedheat sealing case.

In all cases, it is advantageous for the distance ‘d’ between line ofpreferential tearing 5 and the edge of the pouch closest to it—i.e. theupper edge of the pouch in our example—to be greater than 9 mm,preferably 11 mm, more advantageously 13 mm, or even greater than 15 mm,even when the sealing line or lines occupy a strip of width “b” lessthan the preferred minimum values. In effect, a distance thus definedallows the user to get a good grasp on the outer edge region of thepouch adjoining the line of preferential tearing during opening. On theother hand, it is preferable for distance ‘d’ to be less than or equalto 60 mm—more advantageously to 40 mm, or even to 30 mm—in order tolimit the amount of film required to produce the pouch. Regardless ofthe shape of the pouch and the arrangement adopted for the line ofpreferential tearing, it is to be understood that the distance “d”between the line of preferential tearing and the edge of the pouchclosest to it satisfies for each point or at least on average any one ofthese preferred minimum limits throughout that part of the length ofthis pouch edge which faces the line of preferential tearing. Similarly,it is to be understood that the distance “d” satisfies for each point orat least on average any one of these preferred maximum limits throughoutthat part of the length of this pouch edge which faces the line ofpreferential tearing.

The line of preferential tearing 5 extends close to and along thesealing line 9.

The term “line of preferential tearing” refers to any alteration to thestructure of the film forming the side wall of the pouch along a givenline and which weakens the film along this line with the effect that thefilm tears preferentially along this line. The weakening is preferablysuch that a user can tear the pouch along the line of preferentialtearing by means of his hands without resorting to tools.

The line of preferential tearing 5 may be made by any suitabletechnique, especially those known in the prior art.

In particular, the alteration in the film structure may take the form ofa succession of round or oblong blind holes along the line ofpreferential tearing to be defined, or be continuous in nature, that isto say in the form of a single notch or groove extending over the entirelength of the line of preferential tearing to be defined.

For the type of film previously recommended, the holes or the notch maybe made either in the inner plastic layer, or in the outer plasticlayer, or in both. However, it is preferable that the holes do notpenetrate into the light-metal layer in order not to damage its gasbarrier function.

These holes or the notch may especially be made by laser as, forexample, described in WO 98/29312. They may also be made by mechanicalperforation of the plastic layer or layers before assembling the variouslayers of the film as described, for example, in EP-A-1 216 827.

From a more general point of view, it is preferable for the line ofpreferential tearing not to be made in the form of perforations passingthrough the entire thickness of the film forming the side wall in orderto avoid contamination of the closed pouch, even if it is used inapplications not requiring it to be sealed.

The line of preferential tearing 5 is preferably parallel to the sealingline 9. Thus, the stiffness given by the sealing line 9 in the zone ofthe line of preferential tearing 5 is substantially uniform over theentire length of the line of preferential tearing 5.

The line of preferential tearing 5 is preferably straight, whichprovides better guiding for the tear during opening in comparison with acurved line.

The line of preferential tearing 5 extends from a side edge of thepouch, which makes it possible to initiate the tear for opening fromthis edge.

The line of preferential tearing may extend to the other side edge ofthe pouch as shown, which makes it possible to completely open it overthe entire width of the pouch.

The line of preferential tearing 5 may extend into the sealing zone orzones along the side edges 2 and 3, especially if the technique used forproducing the line of preferential tearing does not adversely affect theleak tightness of the seal. Otherwise, it may stop in front of the sidesealing zone or zones.

In particular, when the line of preferential tearing does not extend upto the seal of the side edge, but stops before the latter, it isadvantageous to provide a notch in the seal of the side edge at thelevel of the line of preferential tearing 5. Such a notch makes iteasier to initiate the tear through the side sealing zone on opening inorder to join up with the line of preferential tearing 5 after the sidesealing zone, the tear then propagating along the line of preferentialtearing 5. Such a notch has been shown for each of the side edges 2 and3 by the references 7 and 8.

To obtain good guiding of the tear along the line of preferentialtearing, the distance “a” between the line of preferential tearing 5 andthe sealing line 9 is less than or equal to 10 mm, preferably to 8 mm,more advantageously to 6 mm, even more advantageously to 4 mm, even to 2mm or even better to 1 mm. The closer the line of preferential tearing 5is to the sealing line 9, the better the tear is guided along the lineof preferential tearing on opening. At the minimum, the distance “a” isconsequently 0 mm. In practice one should take account of the tolerancein the positioning of the line of preferential tearing 5 with respect tothe sealing line 9 that the production machinery is capable ofobserving. But there is no disadvantage when part of the width of theline of preferential tearing extends into sealing region 9.

Whatever the shape of the pouch and the arrangement chosen for the lineof preferential tearing, it is to be understood that the distance “a”satisfies any one of the preferred maximum limits previously definedalong at least 50% of the length of the line of preferential tearing 5,more advantageously over at least 75%, or even 90% of its length. It iseven more advantageous for the distance “a” to satisfy any one of thepreferred maximum limits, for each point or at least on average, alongthe entire line of preferential tearing 5.

Where the line of preferential tearing consists of holes, one or moresuccessive notches, one or more successive grooves or any other visiblealteration to the film, the distance “a” is measured between the edge ofthe sealing line facing the line of preferential tearing and themid-line of the holes, the notch(es), the groove(s) or of the visiblealteration to the film. Similarly, the distance “d” between the pouchedge nearest the line of preferential tearing and the line ofpreferential tearing itself is measured between said pouch edge and themid-line of the holes, the notch(es), the groove(s) or of the visiblealteration to the film. An illustration thereof is given by FIG. 3 inwhich the line of preferential tearing is formed by a succession ofoblong holes 5 a.

In the other cases, the distance “a” is measured between the edge of thesealing line on the side of the line of preferential tearing and theedge of the portion of the side wall exhibiting the sealing line whichis obtained through tearing along the line of preferential tearing.Similarly, the distance “d” is measured between the pouch edge nearestthe line of preferential tearing and the edge of the portion of the sidewall exhibiting the sealing line which is obtained through tearing alongthe line of preferential tearing. An illustration thereof is given inFIG. 4 which shows the upper portion of the pouch removed from the restof the pouch after having torn the side wall along the line ofpreferential tearing 5.

To obtain improved guiding for the tear along the line of preferentialtearing, it is advantageous for the second side wall of the pouch alsoto have a line of preferential tearing which is provided at the samelevel as the one on the first side wall. In other words, the two linesof preferential tearing face each other within the machine positioningtolerances. The tear, on opening, thus propagates advantageously in eachside wall along the corresponding line of preferential tearing.

FIG. 5 shows a particularly preferred alternative to the previousembodiment. The description given of the previous embodiment iscompletely applicable to the present embodiment, with the exception ofthe differences mentioned below. In particular, identical referencenumbers denote the same elements.

The embodiment of FIG. 5 is distinguished from the first embodiment bythe fact that the side wall has a second line of preferential tearingreferenced 6.

The second line of preferential tearing 6 extends parallel to the lineof preferential tearing 5 below the level of the latter. The distance“c” between the two lines of preferential tearing 5 and 6 is preferablyless than or equal to 8 mm, more advantageously to 5 mm in order to alsoprovide correct guiding of the tear propagating, as the case may be,along the lower line 6.

Thus, the tear on opening may follow either of the two lines ofpreferential tearing 5 and 6. If the tear leaves one of the lines 5, 6,it may eventually rejoin the other and continue along the latter.

Similarly, it is possible to provide one or more additional parallellines of preferential tearing below the line 6.

Where a line of preferential tearing consists of holes, one or moresuccessive notches, one or more successive grooves or any other visiblealteration to the film, the distance “c” is measured from the mid-lineof the holes, of the notch(es), the groove(s) or of the visiblealteration to the film. FIG. 8 shows a partial view from the top of oneside wall of the pouch in which the two lines of preferential tearing 5and 6 are formed by a succession of holes 5 a and 6 a, respectively.

Otherwise, the distance “c” is measured from the edge of the portion ofthe side wall formed by the line of preferential tearing in questionafter tearing along the latter. An illustration thereof is given in FIG.9 in the case where neither of the two lines of preferential tearing 5and 6 is formed by holes, notch(es), groove(s) or other visiblealteration. The distance “c” is then measured after tearing along eachof the lines of preferential tearing 5 and 6, which provides the stripof film between the latter which is enough to measure the width asindicated.

Moreover, the notch or notches 7, 8 serving to initiate the tear fromthe edge, when they are actually provided, are placed at a level betweenthe two lines of preferential tearing 5 and 6. Thus, the notch ornotches 7, 8 do not need to be positioned at an accurate level on theedge during manufacture unlike the first embodiment. This is because thetear in initiated at a notch is propagated at an intermediate levelbetween the two lines of preferential tearing and rejoins one of them ifthe tear deviates, in which case it propagates along the latter. Toposition the notches 7 and 8 at a level between the two lines ofpreferential tearing 5 and 6, it is preferable for the distance betweenthe two lines of preferential tearing 5 and 6 to be at least equal to 2mm.

Here again, it is advantageous for the second side wall of the pouchalso to have two—or more—lines of preferential tearing similar to thefirst side wall which are provided substantially at the same level asthose on the first side wall. Thus, the tear, on opening, advantageouslypropagates in each side wall along one of the lines of preferentialtearing even if the lines of preferential tearing of each side wall arenot exactly facing each other, but slightly offset to each other becauseof manufacturing tolerances. FIG. 6 illustrates such a pouch at a stagewhere the opening tear is propagated on the line of preferential tearing6 to the middle of the width of the pouch. FIG. 7 shows a partial viewof an upper corner of the pouch before the latter is closed by sealingthe upper edge 1. It shows the two lines of preferential tearing 5, 6present in each side wall 100, 101 at a corresponding level and thenotch 7 located at a level between the lines of preferential tearing 5,6.

FIG. 10 shows a side wall of a pouch according to another embodiment.The description given of the embodiment of FIGS. 2 to 4 appliescompletely to the present embodiment, with the exception of thedifferences mentioned below. In particular, identical reference numbersdenote the same elements.

As in the embodiment of FIG. 2, the pouch of the present embodiment alsohas a single line of preferential tearing 5 on one of the side walls oron both of them. A notch 7 or 8 is provided on at least one edge of thepouch in order to make it easier to initiate the tear in order to openthe pouch. The notch 7 or 8 is placed at a level intermediate betweenthe line of preferential tearing 5 and the edge of the sealing line 9 onthe side of the line of preferential tearing 5. This makes it possibleto initiate the tear, in order to open the pouch, between the line ofpreferential tearing 5 and the sealing line 9. The tear then propagatesbetween the line of preferential tearing 5 and the sealing line 9. Thetear may possibly deviate towards the line of preferential tearing 5until reaching it in which case it continues to propagate along thelatter. Conversely, the tear may deviate towards the sealing line 9until reaching it. In this case, the tear does not cross the sealingline 9, but tends to follow the edge thereof on the same side as theline of preferential tearing 5 because of the increased tear resistancein the sealing zone given by the seal. This is even more the case whenthe initial distance between the tear and the sealing line is smallbecause of the position of the notch and of the line of preferentialtearing and therefore when the angle of attack for the tear towards thesealing line 9 is small. The edge of the sealing line 9 towards the lineof preferential tearing 5 therefore acts as a barrier or guide for thetear, which gives an effect similar to a line of preferential tearing.

For this reason, in this embodiment, it is preferably the distance “e”between the edge of the sealing line on the side of the line ofpreferential tearing and the edge of the pouch closest to the line ofpreferential tearing—i.e. the upper edge of the pouch in ourexample—which is adanrageously greater to 9 mm, preferably 11 mm, moreadvantageously 13 mm, or even greater than 15 mm, even when the sealingline or lines occupy a strip of width “b” less than the preferredminimum values. In effect, the distance thus defined allows the user toget a good grasp on the outer edge region of the pouch extending down tothis edge of the sealing line during opening. On the other hand, it ispreferable for distance “e” to be less than or equal to 60 mm—moreadvantageously to 40 mm, or even to 30 mm—in order to limit the amountof film required to produce the pouch.

Regardless of the shape of the pouch and the arrangement adopted for theline of preferential tearing, it is to be understood that the distance“e” between the edge of the sealing line nearest the line ofpreferential tearing and the edge of the pouch closest to the line ofpreferential tearing, satisfies for each point or at least on averageany one of these preferred minimum limits throughout that part of thelength of this pouch edge which faces the line of preferential tearing.Similarly, it is to be understood that the distance “e” satisfies foreach point or at least on average any one of these preferred maximumlimits over that part of the length of this pouch edge which faces theline of preferential tearing.

Of course, the present invention is not limited to the examples and tothe embodiments described and shown, but it is capable of many variantsaccessible to a person skilled in the art. Thus, the upper edge 1 andthe sealing line 9 of the pouch may be curved instead of straight. Inthis case, the line(s) of preferential tearing may also be curvedinstead of being straight. In particular, their curvature may correspondto a downward translation of the curve defined by the sealing line 9such that the curve formed by the line(s) of preferential tearing isparallel to the sealing line. In the latter case, if the sealing linehas a certain width—that is to say has the shape of a sealing strip—,the curve defined by the sealing line extends as if it were the lineformed by the edge of the sealing line on the same side as the line ofpreferential tearing.

Moreover, the line(s) of preferential tearing 5 and 6 may not extendover the entire width of the pouch from the first side edge 2 to thesecond side edge 3. For example, they may extend from a side edge to themid-width of the pouch so as to limit the opening length of the pouch.In this case, the line(s) of preferential tearing may extend through theupper seal 9 so as to allow the complete removal of the top portion ofthe pouch defined by the line(s) of preferential tearing.

Films other than those described may be used, such as, for example,films not having a light-metal layer and/or using other plastics.

The invention is advantageously applicable to pouches designed tocontain foodstuffs, especially moist foodstuffs. In particular, it isadvantageously applicable to pouches sealed against gas after closure,especially those intended to undergo sterilization treatments by heattreatment. Nevertheless, it is also applicable to pouches which are notsealed against gas. More generally, it is advantageously furtherapplicable to pouches containing loose products of any type. It may forexample be applicable to pouches or bags containing loose confectionery.

The invention is applicable to pouches of any dimensions and shapes.

Where the lines of preferential tearing extend from a side edge towardsanother side edge of the pouch, or even until reaching this other sideedge, especially along an upper sealing line as described in theembodiments, it is preferable for the distance between the side edges ofthe pouch—measured in a straight line at the level of the line(s) ofpreferential tearing along its/their general direction—to be at leastequal to 20 mm, more advantageously to at least 40 mm, moreadvantageously again to at least 60 mm, even to at least 80 mm. This isbecause the wider the pouch at the level of the lines of preferentialtearing, the greater the positive effect of the invention on guiding thetear on opening. In the case of pouches having two parallel sideedges—especially rectangular pouches—and having one or more straightlines of preferential tearing extending perpendicularly to the sideedges, the minimum distance between previously defined side edgescorresponds to the width of the pouch.

Moreover, the height of the pouch—measured from the bottom of the pouchto the lower edge of the sealing line—is preferably at least 60 mm, evenat least 100 mm in order to provide a good handgrip for the user.

The invention is not only applicable to pouches of the “Doypack®” type,but also to any other type of pouch such as flat pouches (called “pillowpouches”) welded on three or four sides or else pouches with sidebellows, as described for example in WO 98/29312.

1-32. (canceled)
 33. A flexible pouch sealed against gas, comprising:two side walls rendered integral by at least a sealing line; and a lineof preferential tearing provided in one of the two side walls, the lineof preferential tearing being arranged for providing access to a contentpackaged in the pouch upon tearing the pouch along the line ofpreferential tearing; wherein the line of preferential tearing extendsalong the sealing line, the distance between the line of preferentialtearing and the sealing line being less than or equal to 6 mm.
 34. Thepouch according to claim 33, wherein the distance between the line ofpreferential tearing and the sealing line is less than or equal to 4 mm.35. The pouch according to claim 33, wherein the line of preferentialtearing extends facing at least one edge of the pouch, the distancebetween the line of preferential tearing and a pouch edge nearest theline of preferential tearing being greater than 9 mm.
 36. The pouchaccording to claim 33, wherein: the line of preferential tearing extendsfrom an edge of the pouch; edges of the walls corresponding to said edgeof the pouch from which the lines of preferential tearing extend aresealed together; and a notch is made in the sealing zone of said edgesof the walls at the line of preferential tearing.
 37. The pouchaccording to claim 33, wherein: the line of preferential tearing extendsfrom an edge of the pouch; edges of the walls corresponding to said edgeof the pouch from which the line of preferential tearing extends aresealed together; and a notch is made in the sealing zone of said edgesof the walls at a level intermediate between the line of preferentialtearing and the sealing line.
 38. The pouch according to claim 37,wherein the distance between the edge of the sealing line towards theline of preferential tearing and the edge of the pouch facing which theline of preferential tearing extends and which is the closest to theline of preferential tearing, is greater than 9 mm.
 39. The pouchaccording to claim 33, further comprising: another line of preferentialtearing provided in the other of the two side walls, this other line ofpreferential tearing lying opposite the line of preferential tearingprovided in the first of the two side walls.
 40. The pouch according toclaim 33, further comprising: a second line of preferential tearingprovided in the side wall in which the first line of preferentialtearing is provided, the second line of preferential tearing extendingparallel to the first line of preferential tearing, the distance betweenthe two lines of preferential tearing being less than or equal to 8 mm.41. The pouch according to claim 40, wherein two other parallel lines ofpreferential tearing are provided in the other of the two side walls,the two other lines of preferential tearing extending opposite the twolines of preferential tearing provided in the first of the two sidewalls.
 42. The pouch according to claim 33, wherein each side wall ismade from a film comprising a light-metal layer held between two plasticlayers.
 43. The pouch according to claim 33, comprising: several sealinglines forming a multi-line sealing strip, the width of this strip beinggreater than 9 mm.
 44. The pouch according to claim 33, wherein eachside wall in which is provided a line of preferential tearing is madefrom a film comprising at least one plastic layer.
 45. The pouchaccording to claim 33, wherein the pouch is of a type intended toundergo heat treatment for preservation treatment.
 46. A flexible pouchsealed against gas, comprising: two side walls rendered integral by atleast a sealing line, the width of the sealing line being greater than 9mm; and a line of preferential tearing provided in one of the two sidewalls, the line of preferential tearing being arranged for providingaccess to a content packaged in the pouch upon tearing the pouch alongthe line of preferential tearing; wherein the line of preferentialtearing extends along the sealing line, the distance between the line ofpreferential tearing and the sealing line being less than or equal to 6mm.
 47. The pouch according to claim 46, wherein the distance betweenthe line of preferential tearing and the sealing line is less than orequal to 4 mm.
 48. The pouch according to claim 46, wherein: the line ofpreferential tearing extends from an edge of the pouch; edges of thewalls corresponding to said edge of the pouch from which the line ofpreferential tearing extends are sealed together; and a notch is made inthe sealing zone of said edges of the walls at a level intermediatebetween the line of preferential tearing and the sealing line.
 49. Thepouch according to claim 46, further comprising: another line ofpreferential tearing provided in the other of the two side walls, thisother line of preferential tearing lying opposite the line ofpreferential tearing provided in the first of the two side walls. 50.The pouch according to claim 46, comprising: a second line ofpreferential tearing provided in the side wall in which the first lineof preferential tearing is provided, the second line of preferentialtearing extending parallel to the first line of preferential tearing,the distance between the two lines of preferential tearing being lessthan or equal to 8 mm; and wherein two other parallel lines ofpreferential tearing are provided in the other of the two side walls,the two other lines of preferential tearing extending opposite the twolines of preferential tearing provided in the first of the two sidewalls.
 51. The pouch according to claim 46, wherein each side wall ismade from a film comprising a light-metal layer held between two plasticlayers.
 52. A flexible pouch sealed against gas, comprising: two sidewalls rendered integral by at least a sealing line; and a line ofpreferential tearing provided in one of the two side walls, the line ofpreferential tearing being arranged for providing access to a contentpackaged in the pouch upon tearing the pouch along the line ofpreferential tearing, in which the line of preferential tearing extendsalong the sealing line, the distance between the line of preferentialtearing and the sealing line being less than or equal to 6 mm; the pouchcapable of containing moist foodstuffs.